Cheapest return flights from Ontario to San Francisco in October from $150

AirHint found the following cheapest return flights from Ontario (ONT) to San Francisco (SFO) in October 2025 (see full year).

Return flights

08 Oct - 22 Oct Southwest Airlines
29 Oct - 05 Nov Southwest Airlines
16 Oct - 20 Oct Southwest Airlines
05 Oct - 12 Oct Frontier Airlines direct
25 Oct - 27 Oct Southwest Airlines
25 Oct - 28 Oct Southwest Airlines
26 Oct - 30 Oct Frontier Airlines direct
20 Oct - 07 Nov Southwest Airlines
12 Oct - 19 Oct Frontier Airlines direct
19 Oct - 30 Oct Frontier Airlines direct
18 Oct - 25 Oct Southwest Airlines
25 Oct - 01 Nov Southwest Airlines
11 Oct - 15 Oct Southwest Airlines
30 Oct - 15 Nov Frontier Airlines
29 Oct - 02 Nov Southwest Airlines
19 Oct - 07 Nov Southwest Airlines

Also check the deals for one-way flights from Ontario to San Francisco in October.

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The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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